Typescript component with generic and Partial

[fabruex]

In Typescript, with the following code, I get an error on descWrong property

type T = {
    key: string,
    desc: string
}

type ObjPartial = Partial<T>

let a: ObjPartial = {
    key: '1',
    // Error: Object literal may only specify known properties, and 'descWrong' does not exist in type 'Partial<T>'
    descWrong: 'Number 1'
}

In Vue, with the following code, I get an error only if all the properties don't exist in T

Child Component

<script setup lang="ts" generic="T">
  const props = defineProps<{
    item: T,
    partialItem: Partial<T>
  }>()
</script>

<template>
  <div>
    {{ item }}
  </div>
</template>

Parent Component

<script setup lang="ts">
    import { ref } from 'vue'
    import Child from './Child.vue';

    const item = ref({
        key: '1', desc: 'Number 1'
    })
    const partialItem1 = ref({
        key: '1', descWrong: 'Number 1'
    })
    const partialItem2 = ref({
        keyWrong: '1', descWrong: 'Number 1'
    })
</script>

<template>
  <!--  NO ERRORS -->
  <Child :item="item" :partial-item="partialItem1" />
  <!-- 
    Type '{ keyWrong: string; descWrong: string; }' has no properties 
    in common with type 'Partial<{ key: string; desc: string; }>'
  -->
  <Child :item="item" :partial-item="partialItem2" />
</template>

Is this the correct behavior? If so, is there a way to set a prop as partial of another prop with generic type?
I want to get an error also for partialItem1

Thanks

Vue SFC Playground

Typescript Playground

[chenxch]

[chenxch]

demo

[fabruex]

I want to get an error also for partialItem1

I asked for this, in your demo you removed the error also for partialItem2

ObjPartial = { key?:string, desc?:string}

In typescript, with this type definition, I can't assign an object with a property different than key or desc, in Vue I can. I only get an error if all the properties don't exist.

[chenxch]

Sry, I misunderstood what you meant and mistakenly thought you wanted to eliminate the error message. At present, it seems that the type push is inconsistent with the Partial one, but there is no error message.